Improvement in reamers



R. J. CROACHER.

Improvement in Reamers.

No. 130,488. Patented Aug. 13,1872

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UNITED STATES PATENT Orrrcn.

BHODOLPHDS J. OROAOHER, OF LITTLE COMPTON, RHODE ISLAND.

IMPROVEMENT IN REAMERS.

Specification forming part of Letters Patent No. 130,488, dated August 13, 1872.

. each other, are obtained when the said blades are brought together, each of the said blades also being formed with a shank on line with its cutting-edge, so that when the same are adjusted and attached to a handle strength and steadiness are secured at the desired point.

In the accompanying drawing, Figure l is a perspective view of my improved reamer. Fig. 2 is a perspective view of reamerwith augerbit attached. Fig. 3 is a transverse view of the blade. Fig. 4 shows the blades detached. The reamer is made of steel, in two parts, each part provided with a cutting-edge. Ais the handle, to which the blades B and O of the reamer are fastened by nuts Fin the usual manner. The blades are of the hollow half-cone form common to reamers, but are each formed with its own shoulder and shank d c, for attachment to the handle in line with the cutting-edges, whereby strength and steadiness are secured at the desired part. The blade 0 is truncated, as shown in Fig. 3, while B tapers to a point, projecting beyond 0. This is the form of the two blades when employed without the auger. The blades B and C have each a beveled cuttingedge, lettered, re-

Near the extremity of blade 0, and at or abouta corresponding point on blade D, and within their concavities, are formed abutments or projections 72., provided with a thread, and acting as a nut for the reception of the bolt which passes through blade B, firmly uniting the reamer in its length.

When the two blades are united the cutting edges project at opposite sides of thehollow cone, formed as will be seen by reference to Fig. 3. Asa transverse section of the blades, when united, would present nearly a true circle, it follows that the hole out must be round.

D is a slotted sliding bar, attached to and adjustable upon blade B by means of thumbscrew 6. G is a scale or gage, marked longitudinally upon the blade B of the reamer, denoting the diameter of the cone at diiferent points.

In order to regulate or determine the size of the hole made, all that will be required is to slide the slotted bar up or down until its lower extremity rests opposite the desired mark, when it can be fixed at that point by tightening the thumb-screw. If it is found to be desirable the scale can be engraved upon the sliding bar D, in which case it would be graded inversely and the thumb-screw considered as the fixed point.

When the anger or bit marked H is to be used with the ream er, and to form a part thereof, both blades are made like the blade marked 0 in Fig. 3, except that they are truncated at a point nearer the apex of the cone, and the lower extremity of the reameris provided with a suitable socket forthe reception of the shank of the auger. The shank of the auger should have a shoulder corresponding in diameter to the diameter of the reamer at their point of union.

Having thus described my invention, what I claim as new, and desire to secure by Letters Patent, is i 1. The two hollow cone-shaped blades B 0, each formed with a cutting-edge, and with a shank, in one piece and in line with each other, and connected with the handle A, the cuttingedges being opposite each other, as herein shown and set forth. p p 2. The improved reamer, consisting of the two hollow cone-shaped blades B (3, each provided with a cutting-edge, b c, and with a shank, d e, for connection with the handle A, said blades being provided with abutments h within their conca"ities,having screw-threaded openings therein to receive the bolt which connects the said blades together, as herein shown and described.

To the aboveI have signed my name this 

